﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
//using System.DirectoryServices.Protocols;
//using System.ServiceModel.Security;
using System.Net;
using System.IO;
using System.IO.Compression;
using System.Text.RegularExpressions;

namespace WebnetUploadApp
{
    /// <summary>
    /// 有关HTTP请求的辅助类
    /// </summary>
    public class HttpWebResponseUtility
    {
        private static readonly string DefaultUserAgent = @"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
        /// <summary>
        /// 创建GET方式的HTTP请求
        /// </summary>
        /// <param name="url">请求的URL</param>
        /// <param name="timeout">请求的超时时间</param>
        /// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
        /// <returns></returns>
        public static HttpWebResponse CreateGetHttpResponse(string url,int? timeout, string userAgent,CookieCollection cookies)
        {
            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "GET";
            request.UserAgent = DefaultUserAgent;
            if (!string.IsNullOrEmpty(userAgent))
            {
                request.UserAgent = userAgent;
            }
			if (timeout.HasValue)
			{  
				request.Timeout = timeout.Value;
			}  
            if (cookies != null)
            {
                request.CookieContainer = new CookieContainer();
                request.CookieContainer.Add(cookies);
            }
            return request.GetResponse() as HttpWebResponse;
        }
		/// <summary>
		/// 创建POST方式的HTTP请求
		/// </summary>
		/// <param name="url">请求的URL</param>
		/// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
		/// <param name="timeout">请求的超时时间</param>
		/// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
		/// <param name="requestEncoding">发送HTTP请求时所用的编码</param>
		/// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
		/// <returns></returns>
        public static HttpWebResponse CreatePostHttpResponse(string url,IDictionary<string,string> parameters,int? timeout, string userAgent,Encoding requestEncoding,CookieCollection cookies)
        {
            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }
            if(requestEncoding==null)
            {
                throw new ArgumentNullException("requestEncoding");
            }
            HttpWebRequest request=null;
            //如果是发送HTTPS请求
            if(url.StartsWith("https",StringComparison.OrdinalIgnoreCase))
            {
                ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
                request = WebRequest.Create(url) as HttpWebRequest;
                request.ProtocolVersion=HttpVersion.Version10;
            }
            else
            {
                request = WebRequest.Create(url) as HttpWebRequest;
            }
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            
            if (!string.IsNullOrEmpty(userAgent))
            {
                request.UserAgent = userAgent;
            }
            else
            {
                request.UserAgent = DefaultUserAgent;
            }

            if (timeout.HasValue)
            {
                request.Timeout = timeout.Value;
            }
            if (cookies != null)
            {
                request.CookieContainer = new CookieContainer();
                request.CookieContainer.Add(cookies);
            }
            //如果需要POST数据
            if(!(parameters==null||parameters.Count==0))
            {
                StringBuilder buffer = new StringBuilder();
                int i = 0;
                foreach (string key in parameters.Keys)
                {
                    if (i > 0)
                    {
                        buffer.AppendFormat("&{0}={1}", key, parameters[key]);
                    }
                    else
                    {
                        buffer.AppendFormat("{0}={1}", key, parameters[key]);
                    }
                    i++;
                }
                byte[] data = requestEncoding.GetBytes(buffer.ToString());
                using (Stream stream = request.GetRequestStream())
                {
                    stream.Write(data, 0, data.Length);
                }
            }
            return request.GetResponse() as HttpWebResponse;
        }

        private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
		{
			return true; //总是接受
		}
//////////////////////////////////////////////////////////////////////////
		public static HttpWebResponse CreatePostHttpResponse(string url, int? timeout, string userAgent, CookieContainer cc, byte[] streamData)
		{
			if (string.IsNullOrEmpty(url))
			{
				throw new ArgumentNullException("url");
			}
			HttpWebRequest request = null;
			//如果是发送HTTPS请求
			if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
			{
				ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
				request = WebRequest.Create(url) as HttpWebRequest;
				request.ProtocolVersion = HttpVersion.Version10;
			}
			else
			{
				request = WebRequest.Create(url) as HttpWebRequest;
			}
			request.Method = "POST";
			request.ContentType = "application/x-www-form-urlencoded";

			request.CookieContainer = cc;
			if (!string.IsNullOrEmpty(userAgent))
			{
				request.UserAgent = userAgent;
			}
			else
			{
				request.UserAgent = DefaultUserAgent;
			}

			if (timeout.HasValue)
			{
				request.Timeout = timeout.Value;
			}

			request.ContentLength = 0;
			//如果需要POST数据
			if (!(streamData == null || streamData.Length == 0))
			{
				request.ContentLength = streamData.Length;
				using (Stream stream = request.GetRequestStream())
				{
					stream.Write(streamData, 0, streamData.Length);
				}
			}
			return request.GetResponse() as HttpWebResponse;
		}
	}
}
